AES Journal Forum

The Modification of Timbre by Resonances: Perception and Measurement

Resonances are fundamental to the production of musical pitch and timbre. they are also the principle source of coloration when they are added in the processes of sound recording and reproduction. The traditional problem in the design and evaluation of audio products has been to find the measurements necessary to recognize the presence of a resonance, the interpretation necessary to characterize its audibility, and the judgment of how much its form must be modified in order for it not to cause objectionable coloration. A review of previous work and new experimental results describe the thresholds of audibility of resonances as a function of frequency. Q, relative amplitude, time delay, program material, listener hearing performance, loudspeaker directivity, and terms of the measured amplitude and time responses of the systems through which the audio signal is passed. While the emphasis is on reproduced sound, there are some interesting relationships to the perceived timbre of sound in live performances.